Spark plug



J. S. WHITTIER SPARK PLUG Manch 11 1924. 1,486,710

Filed June 15 1923 Joseph & .whifiial",

Patented ll Josnrn s. wnrr'rrnn,

01 FECOULTGN, 112L111 SPARK PLUG.

Application filed June 15, 1923.

To all whom it may concern:

Be it known that l, Josnrrr S. Wnrrrmn, a citizen of the United States, residing at Houlton, in the county or" liroostoolr and State of Maine have invented certain new and useful improvements in parlr l lugs, of which the following is a specification.

My said invention relates to a spark plug and it is an object of the same to provide a device of the character described which shall produce a very hot spark, this result being obtained by creating a spark that is hollow and approximately of cylindrical shape.

Another object is to minimize the deposit of carbon on the sparking surface.

Referring to the accompanying drawings, which are made a part hereof and on which similar reference characters indicate similar parts,

Figure 1 is an elevation of my device with parts broken away to show the inner construction,

Figure 2, a bottom plan or" the device with part of one terminal broken away, and

Figure 3, a detail of the terminals on an enlarged scale.

In the drawings reference character 10 indicates the body of a spark plug having the usual external thread 11 and having secured in place therein the usual orcelain body 12. A terminal 13 of ordinary construction is secured in the threaded skirt 11 and this terminal is preferably in the shape of a solid wire bent as shown and having a flat surface at the upper end of the bent part 14. terminal 15 extends through the spark plug as usual, this terminal being bored out at its lower end to produce a cylindrical opening or cup at 16, which opening may of course be formed in any desir able manner and the shape of which may vary to some slight extent without departing from my invention. The conformation of this terminal causes the spark to assume a cylindrical or hollow form and to throw out an unusual amount or" heat thereby more certainly insuring an ignition of the gases in the fuel chamber especially when the engine is cold or when the conditions are otherwise unfavorable.

Serial its. 84-51682.

At 1'? l have indicated a fin or sharp edge tor-med by cutting an annular groove at 18 in the lower end of the terminal. The slot causes eddies in the gas as it rushes past the middle of the cup and this tends to prevent the deposit of carbon on the terminals. By thi construc ion I secure a substantially hollow cylindrical spark which is hotter than spark of the common plug and which is almost carbonprco'f.

Having thus fully described my said invention, what 1 claim as new secure by Letters Patent, is:

1. A spark plug having opposed terminals one t "iinal having a hollow cylindrical con; rination and being externally grooved to form sharp annular in adjacent to its lower end ry as set forth.

2. A spark plug having a rod-like terminal with a face, and an opposed hollow cylindrical terminal with a slot surrounding it near its lower end, substantially as set forth.

3. it spark plug having a rod-like terminal with a fiat end surface, an opposed cylindrical terminal having a cylindrical pocket in its end and an external annular recess formed by an annular cut inclined to the axis of the terminal intersected by a cut substantially at right angles to the axis of said terminal, substantially as set forth.

i. A spark plug having rod-like termi nal with a fiat end surface, an opposed cylindrical terminal having a cylindrical pocket in its end and an external annular recess formed by an annular cut extending inwardly from the circumference of the end of said terminal intersected by an annular cut substantially at right angles to the axis of said terminal, substantially as set forth.

witness whereof, I have hereunto set my hand and seal Houlton, Maine, this thirteenth day oi June, 25.. D. nineteen hundred and twenty-three.

JG SEPH 9;. WHITTIER. [n a] l iitnesses L. J. larimuson,

C. P. Bannns. 

